The art is great, the character design is great, the characters are interesting. But interesting doesn't mean good.
But this author would rather have the MC (main character) change personality instead of tell a consistent story, all for the sake of the gimmick of [the MC isn't allowed to know he has a harem]. That only worked the first time.
With the prostitute character, the setup for the gimmick was so contrived it didn't make sense for several reasons:
1)Her parents kidnapped her without her knowledge... somehow.
2)They were running away because they were terrified of a city lord who has lost his seat of power due to being exposed, who should now be in jail for the rest of his miserable life, and is comatose!
So why were they running away from someone who actually can't ever hurt them again? The gimmick!
The writer clearly doesn't know how to write, as is further evidenced later in the story when the MC meets a king who
woke up from a coma
minutes ago... there was literally no time for the king to become aware of the MC's deeds, never mind reward him for them.
The author forgets important details of the previous stuff they wrote for some reason.
This author is also a moral hypocrite, as they have no qualms about making the MC feel horrible for stuff he didn't do but must make sure all the women get happy endings despite some intentionally making bad choices that normally lead to heartbreak for them.
The prostitute thing was handled so poorly even aside from the core issues MasterSang brought up below (which I 100% agree with).
I'll add my argument on why it was bad story planning. (Honestly, this manga, outside of its world building and art, is a mess. An interesting mess, to be sure, but a mess nonetheless.)
This manga starts out with the MC losing his childhood love to the hero.
I honestly hope so, because the manga only showed that the hero pulled her into an impromptu kiss, with no indication of whether she wanted it or not, and if this whole story started because the MC couldn't even talk to her but she actually was faithful to him...
Say it with me: the gimmick!
Which makes me think that's what happened. And if that's the case and she didn't go after the MC or put up wanted posters or something, and in the end gets back with the MC... well, it will be proof the writer never knew what he was doing in the first place. That said, there's enough proof of that without these hypotheticals.
Getting back to the prostitute arc issue and why, beyond its moral failings, it still fails:
So the MC at this point has had his heart torn asunder twice, and meets the prostitute character. What would make sense here?
A) Giving up on love and using her as a prostitute to dull the pain.
B) Not giving up on love and using her as a prostitute to dull the pain.
C) Not going to a brothel because women are the last thing you want to get intimate with right now due to heartbreak.
You know what actually happens? The MC falls in love with her after talking with her, and she becomes a harem member despite her red flag choices leading up to her situation. She is a woman who chose to be a whore.
She could have...
A) Run away with her family like they did after the city lord was no longer a threat (which makes no sense at that point).
B) Worked a different job considering her debt was so large it didn't matter what she did and there are other opportunities in this world.
C) Saved up money to pay an assassin.
D) Gotten married to any guy of her choice and started a new life with them.
But no, she chose to be a prostitute, she had sex with the guy she supposedly hates, she calls what she did dirty, and the author ignores the MC's circumstances and heartbreak and makes him wax romantic about how all that doesn't matter or make her dirty.
That is the worst possible, most out-of-character thing the MC could have done. The author refuses to be consistent and let her past have consequences on her, and this refusal to be consistent is both a moral failure and, say it with me: for the gimmick!
Because, as mentioned above, the prostitute girl is nonsensically
kidnapped by her family, which prevents her from being with the MC
. This means the MC is heartbroken for the third time, and you know what the MC does?
Well, consistency would screw up the gimmick, so instead the author gives him a screwed up pep-talk convinces him to stop looking for love altogether.
TL;DR:
The initiating event not withstanding, the gimmick works once and is dumb after the first time. Any intelligent and sane person would recognize this and pivot. This author doesn't; they double down at the cost of breaking suspension of disbelief.
Why are so many authors like this nowadays?
But, to be honest, there is still something there to read and be entertained by on occasion.